Memory-intensive applications often suffer from the poor performance of disk swapping when memory is inadequate. Remote memory sharing schemes, which provide a remote memory that is faster than the local hard disk, ar...
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ISBN:
(纸本)9781424400546
Memory-intensive applications often suffer from the poor performance of disk swapping when memory is inadequate. Remote memory sharing schemes, which provide a remote memory that is faster than the local hard disk, are able to improve the performance of such applications. Due to the limitation of being applicable within single clusters only, however, most of the previous remote memory mechanisms, such as the network memory scheme, fail to be extendable into a large scale, distributed, heterogeneous, and dynamic environment. In this work, we propose a service-oriented grid memory sharing scheme, distributed paging RAM grid (DPRG). We study the properties and criteria of large scale memory sharing, and then design major operations and optimizations to fit the usage of grid systems. We collect trace from our grid environment, and evaluate DPRG through comprehensive trace-driven simulations. Results show that DPRG significantly outperforms existing remote memory sharing schemes and supports grid computing applications effectively
This paper proposes a novel conceptual underwater bio-robot inspired by Rhinecanthus aculeatus, which belongs to median and/or paired fin (MPF) propulsion fish and impresses researchers with agility by cooperative und...
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This paper proposes a novel conceptual underwater bio-robot inspired by Rhinecanthus aculeatus, which belongs to median and/or paired fin (MPF) propulsion fish and impresses researchers with agility by cooperative undulation of the dorsal-and-anal fins. Such a fish-like robot is anticipated to outperform the conventional aquatic robots in maneuverability and stability for oceanic exploitation necessities, e.g. benthonic mineral exploration. To begin with, a specimen of R. aculeatus was filmed in a glass aquarium (150cm times 50cm times 60cm) in which artificial seawater was maintained at 26 degC or so. Afterwards, we analyzed a few characteristics in morphology and locomotion with image processing and other approaches. The morphological and kinematical bionic inspirations were summarized, and in succession, we elaborately delineated the design scheme of our conceptual robotic fish including the schematic architectures, the structural and outside form, and the undulatory multi-fin propulsor
Meteorology grid computing aims to provide scientist with seamless, reliable, secure and inexpensive access to meteorological resources. However, the vision of achieving these goals has been encountered with many chal...
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Meteorology grid computing aims to provide scientist with seamless, reliable, secure and inexpensive access to meteorological resources. However, the vision of achieving these goals has been encountered with many challenges such as the degree of easy-to-use and the capability of seamless automation. Fortunately, the emerging semantic Web service and semantic grid technologies bring some significant solutions for the above challenges. Semantic meteorology grid architecture (SMGA) is being developed by us to support automated meteorology grid service discovery, selection, and composition. In this paper, we present a model for semantic annotation and publication of meteorology grid services by combining the expressive power of the present ontology language and the advantages of semantic Web techniques. The presented model is an initial work to support automating the discovery, selection, and workflow composition of semantically described heterogeneous meteorological services, which offers the possibility of facilitating geographically distributed meteorological scientists to resolve complex scientific problems cooperatively
This article assesses the performance of a virtual pheromone-based sectored dispersion algorithm which is implemented on a low-cost miniature mobile robotic platform using sonar sensing. The approach is a distributed ...
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This article assesses the performance of a virtual pheromone-based sectored dispersion algorithm which is implemented on a low-cost miniature mobile robotic platform using sonar sensing. The approach is a distributed one and the robotic platform and sensor array are sufficiently inexpensive that they can be employed in undergraduate research and/or for coursework in a small college environment
Many scientific computing applications demand a great amount of memory, which are usually run on supercomputers with large physical memory. The applications whose complete time is affected by memory capacity, is usual...
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Many scientific computing applications demand a great amount of memory, which are usually run on supercomputers with large physical memory. The applications whose complete time is affected by memory capacity, is usually called memory-intensive applications. Many disk 10 operations will be caused by memory-intensive applications due to insufficient physical memory of computing environment, which depress the system performance dramatically. Traditional network memory or memory server schemes try to share free memory of idle nodes in the cluster, while it is often influenced by heavy cluster loading or interior network congestion. Combining the network memory with current service computing and grid computing technology, a memory service based memory sharing grid system named RAM Grid, is proposed. RAM grid improve traditional network memory scheme, and extend the application area of grid computing. As one of the major computing resources, memory can be shared on the Internet through RAM grid, such as computing power and disk storage being shared through computational grid and data grid. The system criteria and properties are analyzed. One of the system schemes is also proposed in detail. Through the real trace based simulation, the performance of RAM Grid is evaluated and proved better than traditional network memory or disk IO obviously.
The conjugate residual (CR) algorithm is a Krylov subspace algorithm that can be used to obtain fast solutions for symmetric linear systems with very large and very sparse coefficient matrices. By changing the computa...
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The conjugate residual (CR) algorithm is a Krylov subspace algorithm that can be used to obtain fast solutions for symmetric linear systems with very large and very sparse coefficient matrices. By changing the computation sequence in the CR algorithm, this paper proposes an improved Conjugate Residual (ICR) algorithm. The numerical stability of ICR algorithm is same as CR algorithm, but the synchronization overhead that represents the bottleneck of the parallel performance is effectively reduced by a factor of two. And all inner products of a single iteration step are independent and communication time required for inner product can be over lapped efficiently with computation time of vector updates. From the theoretical and experimental analysis it is found that ICR algorithm is faster than CR algorithm as the number of processors in creases. The experiments performed on a 64-processor cluster indicate that ICR is approximately 30% faster than CR.
Dynamic scheduling algorithms for real-time multiprocessor are important components of real-time systems. In this paper, a new algorithm, named Group-Proper (GP), is presented based on analysis of the shortcomings of ...
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Dynamic scheduling algorithms for real-time multiprocessor are important components of real-time systems. In this paper, a new algorithm, named Group-Proper (GP), is presented based on analysis of the shortcomings of myopic algorithm and thrift algorithm. GP algorithm includes two policies: grouping policy and properly choosing policy (PCP). Grouping policy is aimed to increase the utilization of resources. PCP is aimed to enlarge the utilization of CPU. On the condition of ensuring not missing the deadlines of tasks with smaller heuristic value, grouping policy prior chooses the task accessing resources in the shared mode to extend. If a task needn't access resources or the earliest available times of resources required by it are earlier than that of the CPU, PCP assigns the task to the CPU with the earliest available time. Otherwise, PCP assigns the task to the CPU with the closest available times to that of the resources required by it. Simulation results show that acceptance ratio of GP algorithm is higher than that of myopic and thrift.
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